Your desktop can be an efficient place to work. Every time you start KDE, you can see the complete files, folders and URLs which you often use.
There are two ways to create and edit files on your desktop. In any application, you can say that you want to save your work in the Desktop subfolder of your home directory. For example, my home directory is /home/stupiddog, so my Desktop directory is /home/stupiddog/Desktop. Everything you save there will be put on your desktop.
If you want to move existing files to your Desktop, the best way to achieve this is to use Konqueror. Open a file manager window and drag the files you need to your desktop. You can choose to copy them if you want to keep all your common stuff on the desktop now, or you can create symbolic links to the real files. Everything you change in the link files will be automatically updated in the originals. For more information on how to use drag & drop and the file manager, see the chapter Moving files with drag & drop.